FELINE RETROVIRUS MANAGEMENT GUIDELINES THIS IS AN ABRIDGED VERSION OF THE FULL GUIDELINES AVAILABLE AT CATVETS.COM FROM THE AMERICAN ASSOCIATION OF FELINE PRACTITIONERS SPX 0916 IDEXX AAFP Guide_F.indd 1 12/22/08 8:41 AM About These Guidelines This report is an abridged version of the Retrovirus Guidelines of the American Association of Feline Practitioners (AAFP)1 to guide veterinary practitioners who want to optimize the care and management of feline patients. It represents a consensus of current information compiled by the researchers and practitioners on the panel. The AAFP is a professional organization of practitioners and board-certified specialists who seek to raise the standards of feline medicine and surgery among practitioners. MEMBERS OF THE ADVISORY PANEL Julie Levy, DVM, PhD, DACVIM, Chair Eliza Sundahl, DVM, DABVP Maddie’s Shelter Medicine Program (Feline practice) College of Veterinary Medicine KC Cat Clinic University of Florida Kansas City, MO Gainesville, FL Vicki Thayer, DVM, DABVP Cynda Crawford, DVM, PhD (Feline practice) Maddie’s Shelter Medicine Program Purrfect Practice College of Veterinary Medicine Lebanon, OR University of Florida Gainesville, FL Regina Hoffmann-Lehmann, Dr. Med. Vet.,Dr. Habil, FVH Katrin Hartmann, Dr. Med. Vet., Vetsuisse Faculty Dr. Habil., DECVIN-CA University of Zurich Clinic of Small Animal Medicine Zurich, Switzerland Ludwig Maximilian University Munich Munich, Germany Susan Little, DVM, DABVP (Feline practice) Winn Feline Foundation 1805 Atlantic Avenue Manasquan, NJ The guidelines in this report are based on the best research data, clinical experience and technical judgments available at the time of preparation. While the guidelines are as accurate and comprehensive as possible, they are subject to change should new insights become available from additional research or technological updates. 2 American Association of Feline Practitioners SPX 0916 IDEXX AAFP Guide_F.indd 2 12/22/08 8:41 AM Introduction Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are among the most common infectious diseases of cats. Risk INTRODUCTION factors for infection include male gender, adulthood, and outdoor access, whereas indoor lifestyle and sterilization are associated with reduced infection rates.2–6 The retroviral status of all cats should be known. Cats may require retrovirus testing at different times in their lives. Here are some general principles for retrovirus testing: A cat with a confirmed-positive test result should be diagnosed as having a retroviral infection – not clinical disease. Diseases in cats infected with FeLV or FIV may not necessarily be the result of the retrovirus infection. Cats infected with FeLV or FIV may live for many years. A decision for euthanasia should never be made solely on the basis of whether or not the cat is infected. No test is 100% accurate at all times under all conditions. All test results should be interpreted along with the patient’s health and prior likelihood of infection. All positives should be confirmed by another test method. While they can be life-threatening viruses, proper management can give infected cats longer, healthier lives. The following guide reflects the recommendations of the AAFP on managing these infections. Feline Retrovirus Management Guidelines 3 SPX 0916 IDEXX AAFP Guide_F.indd 3 12/22/08 8:41 AM Epidemiology The prevalence of FeLV infection has reportedly decreased during the past 20 years, presumably as a result of implementation of widespread testing programs and development of effective vaccines.2, 3, 7 In contrast, prevalence of FIV has not changed since it was discovered in 1986. In a study of more than 18,000 cats tested in 2004, 2.3% were positive for FeLV and 2.5% were positive for FIV.1 (See opposite page.) Infection rates for FeLV (Column 4) and FIV (Column 5) varied among various subpopulations and sources of cats. FeLV and FIV Diseases Although many cats experience prolonged survival, retroviral infections can also be associated with: Anemia Similar to FIV, it is now thought that cats that become Secondary and opportunistic infected with FeLV remain infected for life. infections Neoplasia Pathogenesis Chronic inflammatory 4 4 WEEKS TO MONTHS 4 4 4 4 MONTHS TO YEARS 4 4 conditions Transmission Viremia Viral Propagation to Other Tissues Asymptomatic Progressive Infection Ocular Disorders – Vertically from – Virus shed in – Targets lymphoid organs (thymus, spleen, Phase – Infection not contained infected queens to saliva, nasal lymph nodes) – Virus replicates in lympth nodes and bone marrow Hematologic FeLV kittens secretions, – Immune response unable to clear infection – Eventually develop FeLV-associated diseases disorders – Horizontally among feces, milk and cats that live urine9,10 Regressive Infection Specific diseases – Cat remains infected but reverts to an aviremic state together or fight associated with very – No antigen or culturalable virus in circulation Clinical Signs Fever, lymphadompathy, leukopenia high rate of infection: – FeLV proviral DNA may be detectable in blood via PCR – Unlikely to shed virus or develop FeLV-associated diesase Cutaneous abscesses (FeLV Transmission Viremia Viral Propagation Asymptomatic Remain Asymptomatic 8.8%, FIV 12.7%)8 – Via bite wounds – High – Drop in Lymphocyte Count Phase – Many cats FIV – Horizontally concentration – Inversion of T-lymphocyte ratio (CD4:CD8) – Lifespan may be normal to moderately decreased Oral inflammation among cats that in saliva – Immune response unable to clear infection Progressive Dysfunction of Immune System (FeLV 7.3%, FIV live together is – Cell medicated immunity compromised and is characterized by chronic inflammatory 12 uncommon Clinical Signs Fever, malaise, diarrhea 7.9%) conditions such as neoplasia and infections with intracellular organisms 4 American Association of Feline Practitioners SPX 0916 IDEXX AAFP Guide_F.indd 4 12/22/08 8:41 AM E PI DEMIOLOGY & PAT Table – Risk factors for FeLV and FIV seropositivity in 18,038 cats tested at veterinary clinics and animal shelters in North America. No. of Cats FeLV FIV Factor Categories Tested No. with Positive No. with Positive HOG Results (%) Results (%) ENE Animal Shelter 8,068 124 (1.5) 141 (1.7) Study Site SIS Veterinary Clinic 9,970 285 (2.9) 305 (3.1) West 3,737 39 (1.0) 72 (1.9) Canada 325 8 (2.5) 10 (3.1) Region South 6,359 144 (2.3) 183 (2.9) Northeast 3,747 107 (2.9) 79 (2.1) Midwest 3,870 111 (2.9) 102 (2.6) Clinic – Indoors Only 3,613 53 (1.5) 32 (0.9) Clinic – Outdoors Access 6,357 232 (3.6) 273 (4.3) Source Shelter – Relinquished Pet 2,809 41 (1.5) 38 (1.4) Shelter – Stray 4,550 71 (1.6) 75 (1.6) Shelter – Feral 709 12 (1.7) 28 (3.9) Juvenile 9,556 131 (1.4) 100 (1.0) Age Adult 8,482 278 (3.3) 346 (4.1) Spayed Female 2,611 45 (1.7) 82 (1.2) Castrated Male 2,984 88 (2.9) 127 (4.3) Sex Sexually Intact Female 6,588 128 (1.9) 44 (1.7) Sexually Intact Male 5,855 148 (2.5) 193 (3.3) Healthy 15,312 238 (1.6) 280 (1.8) Health Status Sick 2,726 171 (6.3) 166 (6.1) 4 4 WEEKS TO MONTHS 4 4 4 4 MONTHS TO YEARS 4 4 Transmission Viremia Viral Propagation to Other Tissues Asymptomatic Progressive Infection – Vertically from – Virus shed in – Targets lymphoid organs (thymus, spleen, Phase or – Infection not contained FeLV infected queens to saliva, nasal lymph nodes) – Virus replicates in lympth nodes and bone marrow kittens secretions, – Immune response unable to clear infection – Eventually develop FeLV-associated diseases – Horizontally among feces, milk and cats that live urine9,10 Regressive Infection – Cat remains infected but reverts to an aviremic state together or fight – No antigen or culturalable virus in circulation – FeLV proviral DNA may be detectable in blood via PCR – Unlikely to shed virus or develop FeLV-associated diesase Transmission Viremia Viral Propagation Asymptomatic Remain Asymptomatic – Via bite wounds – High – Drop in Lymphocyte Count Phase or – Many cats FIV – Horizontally concentration – Inversion of T-lymphocyte ratio (CD4:CD8) – Lifespan may be normal to moderately decreased among cats that in saliva – Immune response unable to clear infection live together is Progressive Dysfunction of Immune System – Cell medicated immunity compromised and is characterized by chronic inflammatory uncommon conditions such as neoplasia and infections with intracellular organisms Feline Retrovirus Management Guidelines 5 SPX 0916 IDEXX AAFP Guide_F.indd 5 12/22/08 8:41 AM Preventing FeLV and FIV Infection Vaccines are available for both retroviruses. Both FeLV and FIV vaccines are non-core. Risk assessment of the individual animal should dictate their use. No vaccine is 100% effective and repeat testing should be performed as warranted. FeLV VACCINATION Because sufficient protection is not induced in all vaccinates, vaccination against FeLV The decision to vaccinate an individual cat does not diminish the importance of testing against FeLV should be based on the cat’s risk cats to identify and isolate those that are of exposure. Cats that live in a FeLV-negative, viremic. In addition, cats should be tested for indoor environment are at minimal risk. FeLV infection before initial vaccination and FeLV vaccination is recommended for: whenever the possibility exists that they have been exposed to FeLV since they were last all kittens because the lifestyles of kittens tested. Administering FeLV vaccines to cats frequently change after acquisition and they confirmed to be FeLV-infected is of no value. may subsequently become at risk for FeLV exposure FIV VACCINATION cats that go outdoors The decision to vaccinate a cat for FIV is cats that have direct contact with cats complicated. FIV vaccines may be considered of unknown status or in high turnover for cats whose lifestyles put them at high risk situations such as foster homes or other of infection, such as outdoor cats that fight group housing or cats living with FIV-infected cats.